1. Field of Invention
The present invention relates to a treatment liquid for a plastic film. More particularly, the present invention relates to a treatment liquid composition to be used in the printing of a water-based ink composition on a recording medium having a recording face formed of a plastic film, which treatment liquid composition is coated onto the recording face before printing of a water-based ink composition. The present invention also relates to a primer liquid to be used for printing for a plastic film. More particularly, the present invention relates to a primer liquid composition to be used in the printing of a water-based ink composition on a recording medium having a recording face formed of a plastic film, which primer liquid composition can be coated onto the recording face before printing of a water-based ink composition to form a primer film. Further, the present invention relates to an ink composition for a plastic film. More particularly, the present invention relates to an ink composition suitable for use for an ink jet recording medium having a recording face formed of a plastic film. Furthermore, the present invention relates to an ink jet recording method using the above treatment liquid, primer liquid, or ink composition.
2. Background Art
An ink jet recording method is a printing method in which droplets of an ink composition are flied to and deposited onto a recording medium in its recording face to perform printing. This method has a feature that high-resolution and high-quality images can be printed at a high speed with a relatively inexpensive apparatus. Regarding recording media for ink jet recording, there is an increasing demand for proper properties of materials constituting the recording media, for those of commonly used papers and the like, as well as plastic films.
Plastic recorded matters produced by printing onto plastic films or the like are expected to be used in applications for which paper cannot be used, for example, outdoor signs. Accordingly, higher waterfastness and lightfastness are required of plastic recorded matters. Also regarding prints such as labels which are touched by the hand, plastic recorded matters are more suitable than paper printed matters. Also in this case, fastness properties such as fastness to rubbing/scratch are required of the recorded matters.
When ink jet recording is carried out using non-surface-treated plastic films for ink jet recording as an ink jet recording medium, for example, non-surface-treated polyvinyl chloride films, solvent-type inks, UV-curable inks, or two-component-type curable inks have hitherto been used. Solvent-type inks, however, emit odor of solvents, and, in some cases, harmful components are contained in the solvent volatile component. Also for UV curable inks, two-component-type curable inks and the like, in some cases, the curable monomer used contains harmful components.
When ink jet recording is carried out using a conventional water-based ink on a non-surface-treated plastic film for ink jet recording, recorded images are unsatisfactory in adhesion, scratch resistance and waterfastness.
Regarding the use of plastic films for ink jet recording, Japanese Patent Laid-Open Publication No. 286940/1997 proposes a method in which a colorant or a dispersing resin as the ink component is coagulated and cured using a water-based ink.
Further, for example, Japanese Patent Laid-Open Publication No. 11486/2003 discloses an ink jet recording method using a pretreatment liquid. This recording method, however, aims to record high-quality and waterfast images on commonly used recording media but does not aim at printing on plastic films. Furthermore, for example, Japanese Patent Laid-Open Publication No. 114140/1998 describes that an amide-containing reaction solution is used in an ink jet recording method using two liquids. In this reaction liquid, the amide is added from the viewpoint of improving print quality and print stability, and this publication does not suggest printing onto plastic films.
On the other hand, for example, Japanese Patent Laid-Open Publication No. 103785/2002 discloses that, in an ink composition for ink jet recording, lactams or lactones can be used as carrier medium materials (see, for example, claim 12 and the like in this publication). This publication, however, describes lactams and lactones only as an example of solvents for dissolving a colorant in an ink composition and does not suggest printing of the ink composition onto a recording medium having a recording face formed of a plastic film.
Further, Japanese Patent Laid-Open Publication No. 48934/2001 discloses an ink composition containing a cyclic amide compound, and Japanese Patent Laid-Open Publication No. 96345/2003 discloses that 2-pyrrolidone, caprolactam and the like are usable as wetting agents in ink compositions. These publications, however, do not suggest advantageous printing of an ink composition onto a recording medium having a recording face formed of a plastic film.
Accordingly, the development of an ink jet recording method using a water-based pigment ink, which can produce plastic recorded matters having excellent waterfastness and rubbing resistance, has been desired.